Catheter

ABSTRACT

A catheter for the creation of an atrial septal defect without thoracotomy. The catheter comprises a main flexible tubular housing and a branch tubular housing. A flexible guide wire extends through the main housing and is secured at the distal end thereof and extends outwardly of the distal end. The guide wire can be deformed into a dome shape protruding from a slit opening in the distal end of the main housing by advancing the guide wire from the proximal end of the main housing. A tiny surgical blade disposed in the slit opening of the main housing is elevated to a desired angle by advancing a flexible control wire pivoted to the blade and extending through the main housing. The branch tubular housing communicates with the main housing and is adapted for connecting a syringe or pressure gauge. A pair of rubber stoppers are provided on the main housing.

United States Patent Park 1 1 CATHETER [72] Inventor: Sang C. Park,87-30 Justice Ave.,

Elmhurst, NY. 11373 221 Filed: June30, 1971 2| Appl.No.: 158,449

[52] US. Cl ..l28/305, 128/DIG. 9, 128/DIG, 16 [51] Int. Cl. .A61b17/32, A6lm 25/00, A61m 29/00 [58] Field of Search ..128/2.05, 304, 305,DIG. 9,

Chesterman, Judson T. AfNew Valvulotome," In The Lancet, July 30, 1955.p 232.

Rastan, H. et al., A New Method of Closed Atrioseptectomy for PalliativeTreatment of Complete Trans- I [151 3,704,711 51 Dec.5,1972

position of the Great Vessels. In .lour. Thoracic and CardiovascularSurgery, 615: 705-709. 1971 Primary Examiner-Channing L. PaceAttorney-Jacob L. Kollin [5 7] ABSTRACT A catheter for the creation ofan atrial septal defect without thoracotomy. The catheter comprises amain flexible tubular housing and a branch tubular housing. A flexibleguide wire extends through the main housing and is secured at the distalend thereof and extends outwardly of the distal end. The guide wire canbe deformed into a dome shape protruding from a slit opening in thedistal end of the main housing by advancing the guide wire from theproximal end of the main housing. A tiny surgical blade disposed in theslit opening of the main housing is elevated to a desired angle byadvancing a flexible control wire pivoted to the blade and extendingthrough the main housing.

The branch tubular housing communicates with the main housing andisadapted for connecting a syringe or pressure gauge. A pair of rubberstoppers are provided on the main housing.

4 Claims, 5 Drawing Figures PATENTED DEC 5 I972 hnu IIIIl lllfl'l I I II I z I I I F/G.3 SU l INVENTOR.

5mm 0. PARK A TTORNEY CATHETER My invention relates to catheters ingeneral, and in particular toa novel catheter for the creation of anatrial septal defect without thoracotomy.

- For the past two decades, surgical creation of atrial septostomy hasbeen known to be a palliative procedure in certain types of congenitalheart disease, particularly in the transposition of the great arteries.However, this procedure carries a significant surgical mortality. Afterthe introduction of a new catheter, namely the Balloon Catheter in 1966by Rashkind, atrial septostomy without thoracotomy or opening of thechest wall surgically become possible. This catheter is equipped with aninflatable balloon at the catheter tip. In order to use this procedure,the catheter is advanced into the heart through a peripheral vein,usually the femoral vein. The catheter tip is then advanced into theleft atrium through the patent foramen ovale, naturally existing hole inthe atrial wall, under fluoroscopic control. The balloon at the cathetertip is inflated with a radium-opaque contrast material. Pulling thisballoon catheter out abruptly and forcefully results in the breakage ofthe atrium septum.

Since the introduction of the balloon technique, mortality of patientswith congenital heart diseases, such as the transposition of the greatarteries in early infancy, has been reduced and a number of infants weresaved at a life-threatening critical moment. The grim outlook for thosepatients has been brightened.

The use of this balloon catheter was promptly popularized with a greatdeal of enthusiasm. After several years of experience with the ballooncatheter some technical and mechanical difficulties were encountered.Also, a few complications in use of this catheter were reported.

The original inventor of the balloon catheter, Dr.

Rashkind, described theoretical problems in the use of the catheter inhis original paper in 1966. Listed problems were as follows: (1)inability to pass the catheter through the patent foramen ovale, (2) Theleft atrium being too small to allow balloon inflation, (3) impairmentof the return of venous blood due to slow emptying of the balloon, (4)rupture of the balloon, and (5 misplacement of the balloon into theright ventrical or other chamber. Subsequently, other investigatorsreported complications: l) inability of deflation of the balloon whilethe catheter tip was still inside of the heart, (2) fatal systemicarterial embolization (occlusion) by a fragment of rubber, as a resultof rupture of the balloon during the procedurethe occlusion of the renalartery on one occasion and the cerebral artery involvement in another.

Furthermore, recent studies indicated that passage of the balloonthrough the foramen ovale has to be performed rapidly since the balloonshuts off the entire systemic output, which resulted in a precipitousdrop of arterial pressure. A longer occlusion of the foramen ovale bythe balloon may result in severe bradycardia, a slowing of the heartrate.

Current balloon atrial septostomy requires multiple pulls with vigorousand rapid force which undoubtably enhances the probability of the abovecomplications and trauma to the adjoining the cardiac tissue.

Not infrequently, in spite of multiple pulls with the balloon catheter,adequate atrial septostomy could not be created. The reason for thisfailure could be an anatomically unusually thick atrial septum andmechanical or technical inadequacies.

The aim of the invention is to eliminate previously noted complicationsin the use of the balloon catheter and to carry out the atrialseptostomy more effectively.

The primary object of the invention is to create an atrial septal defectin infants with various congenital heart disease, particularly ofcyanotic variety, without a thoracotomy. Furthermore, the usage of thecatheter may extend to valvulotomy in either valves of the great vesselsor the atrio-ventricular valves.

Another object of the invention is to create a palliative atrialseptostomy for certain type of the congenital heart disease, wherebyrisky thoracotomy may be eliminated in critically ill newborns and younginfants.

Yet another object is to make possible the performance of a valvulotomyfor either a therapeutic or an experimental purpose without athoracotomy which is, at times, too dangerous to a critically illpatient and alters a great deal of hemodynamics and physiology.

This and other important objects of the invention will become apparentfrom the study of the following description and the accompanyingdrawing.

' It is to be understood, however, that these are given by way ofillustration and not asa' limitation and that various changes in detailconstruction, size and shape of parts may be made within the scope ofthe invention.

In the drawing:

FIG. 1 is a perspective view of the catheter in nonoperative position;

FIG. 2 is an enlarged detail view in vertical cross-section of thedistal part of the catheter in non-operative position, the operativeposition being shown in dotted lines;

FIG. 3 is a top plan view of the same;

FIG. 4 is a schematic view, partly in section, illustrating the catheterin operative position in a heart, just prior to an incision, and

FIG. 5 is an enlarged partial detail of the catheter shown in FIG. 4.

Referring now to the Figures in detail, the catheter, generallyindicated by the numeral 6, comprises a long round thin walledpolyethylene housing tube 8, 14 inches in length with a diameter ofFrench No. 5, which may vary from No. 4 to No. 6. The proximal part ofthe catheter is branched or Y-shaped into two portions, branch 10 and12. The branch portion 10 is 1% inches long and the branch portion 12 isa 2% inches long. The two branch portions are secured with a plasticY-fitting 11 or molded integrally with one another, branch 12 being usedfor connecting a syringe or pressure gauge. The tip 14 of the catheteris provided with a slit 16 on the long axis of the catheter. The slit is0.75 inch long and 0.031 inch wide. The catheter is equipped with a tinysurgical blade 18, a control wire 20 pivoted to one end of the blade at22 and a guide wire 24. The distal portion of the guide wire is a veryfine coiled spring of flexible wire, which has a diameter of 0.025 inch.The flexible part of the guide wire is permanently secured in theforward portion of the tip of the catheter. An end 30, measuring 0.31inch, of the wire protrudes outwardly of the catheter tip 14. The guidewire is disposed in the slit above of the blade 18. The flexible portion21 of thewire extends 2 inches backwards from its securement point inthe catheter tip, and the remainder of the guide wire is stiffened by asolid wire reinforcement inside of the coil spring wire.

As shown in the Figures the fine tiny surgical blade 18 measuring mm X0.8mm X 0.3mm is linked at its other. end at 26 to one end of a lever 28of stainless steel. The other end of the lever is pivoted to the wall ofthe catheter housing at 31 and is made of fine stainless steel wire0.010 inch in diameter which remains inside of the catheter housing.

Both the blade control and the guide wires extend outwardly through theshort branch 10 of the catheter 1% inches and 2 inches, respectively.The free ends of the wires are looped to form a round ring shape 32 forthe guide wire and a triangular shape 34 for the blade wire. These loopsserve as grips for the wires and also by their shapes provide theiridentifications. The long branch 12 is. to be used in known manner forfluid infusion through the catheter and also for pressure measurement.

' A pair of short rubber stoppers 36 and 38 are secured to the catheterhousing one located in the middle of branch l0, theother just distal tothe Y-fitting. These stoppers function by simple clamping withconventional hemostat clamps (not shown). Stopper 36 prevents a fluidleakage and pressure dissipation through branch 10. Stopper 38 is usedto prevent a back flow of blood during the initial introduction of thecatheter into the vessels and cardiac chamber.

MANIPULATION OF THE CATHETER The catheter is introduced into thevessels, usually via the femoral vein 3], by the conventional cutdowntechnique. Then the catheter is advanced into the left atrium 25. Theflexible part 21 of the guide wire is then advanced towards the cathetertip to form a domeshaped loop 40. By gently moving the catheter back andforth an idea of the size and location of the septum 23 can be learned.

After the location of the septum is determined, the guide wire loop 40can be readjusted to the desired direction, by simply rotating theentire catheter, to make the incision in the septum. The blade controlwire is then advanced to form an inverted V protrusion, as shown indotted lines in FIG. 2. The angle and height of the blade can beadjusted as clinically indicated.

To make the incision in the atrial septum, the entire catheter is slowlywithdrawn until the blade 18 crosses the atrial septum. After hismaneuver, control 20 is retracted to fold the blade into the catheter,then similarly, the guide wire 24 is retracted to its originallongitudinal position. Thus, the catheter may be re-advanced again intothe left atrium and a domeshaped loop formed again. By using the guidewire loop 40, the result of the incision may be evaluated. Depending onthe result, the same procedure may be repeated in the same sequence toobtain the optimal result.

After the desired incision has been made and prior to total withdrawalof the catheter, both the wire loop and the blade must be folded backinside the catheter, into the initial non-operative position shown inFIG. 2 to prevent damage to the vein during the withdrawal.

The pressure branch 12 of the catheter serves as a route of fluid orcontrast material administration, pressure measurement and bloodsampling for oxymetry, through the catheter. Another important role ofthe pressure branch of the catheter is to prevent a blood clottinginteriorly of the catheter system by a continuous drip of theanticoagulated fluid.

In order to measure the pressure of the cardiac chamber or vessel inwhich the catheter tip is placed, the guide wire 24 should first bepushed inward to open the side hole of the catheter tip. Then the rubberstopper 36 is clamped with a hemostat to prevent a pressure dissipationthrough the wire control branch. A pressure gauge (not shown) is thenconnected to the pressure branch 12 of the catheter.

in order to clean the guide wire control branch 10 of the catheter, therubber stopper 38 is first clamped, the flushing fluid is then injectedinto the pressure branch 12 of the catheter.

This newly devised catheter can be used for atrial septostomy moreeffectively and eliminates the complications currently arising with theuse of the balloon catheter.

1. This catheter is equipped with a flexible wire tip which minimizesthe trauma or perforation of the cardiac wall or'vessels during themanipulation of the catheter, also, the wire tip would decrease thechances of crossing any intra-atrial communication, such as the patentforamen ovale, even in the presence of a very small hole.

2. The space occupied in the left atrium by the catheter, including thewire loop and blade in the cardiac chamber, is negligible; therefore,the hazard of venous obstruction which occurs with the inflated balloonis eliminated. Also, even in the presence of a small left atrium, atrialseptostomy could be performed.

3. Compared to the blind and forceful atrial septostomy by a ballooncatheter, this catheter is capable of performing an incision on theatrial septum accurately in the desired direction and location. Thisprocedure requires practically no force, which eliminates, withcertainty, unnecessary trauma in adjoining tissue.

. There is no problem with embolization by a foreign body, which hasoccurred in the use of the balloon catheter as a result of the ruptureof the balloon.

5. Misplacement of the catheter into other cardiac chambers can bedetected by careful examination of the guide wire loop and by directpressure measurement.

ADVANTAGES OF CONSTRUCTION 1. Size and manipulation of the catheter ispractically identical as conventionally utilized ones.

2. Because the catheter is equipped with a flexible guide wire tip andloop, manipulation of the catheter is more convenient and the chance ofentering the stenotic area (valve) of the heart is increased.

3. The guide loop wire will serve as an indicator of the direction ofthe scalpel which allows a precise incision of the tissue. Also the loopwill be used in determination of a location or size of the septum orvalves. An additional virtue of this loop wire is to prevent aninadvertent damage of the surrounding tissue as the blade is in use. 4.The height of the blade is easily adjustable. lclaim l. A catheter forthe creation of an atrial septal defect without thoracotomy, comprising,in combination, a main tubular housing of flexible material having anopen end and a closed end tip formed with an elongated slit openportion, a flexible guide wire displaceable longitudinally in said maintubular housing, one end of said guide wire extending outwardly throughsaid open end, the other end of said guide wire being secured in saidclosed end tip and extending outwardly thereof, said other end of theguide wire having a distal part lying within said open slit portion andbeing deformable into a dome-shaped protrusion upon advancing said guidewire in the direction of said closed end tip, a flexible control wiredisplaceable axially of said main housing and having a proximaloutwardly extending end, a blade having one end pivoted to the distalend of said control wire, link means pivoted to the other end of saidblade and to said closed end tip, said blade and said link means beingnormally disposed in said slit open end and deformable into V-shape uponadvancing the control wire in the direction of the closed end tip, abranch tubular housing communicating with said main housing and having afree end adapted for connecting a syringe or pressure gauge, first andsecond stoppers of resilient material secured, respectively, about themain housing forwardly and posteriorly of said branch housing forapplying hemostats to prevent fluid leakage, pressure and back flow ofblood during the initial introduction of the catheter into the vesselsand cardiac chamber of a patient.

2. A catheter as claimed in claim 1, wherein said guide wire consists ofa fine coiled spring wire, and a flexible solid wire secured in saidcoiled spring wire inwardly of the proximal part of said guide wire.

3. A catheter as claimed in claim 2, wherein the one end of said guidewire extending from said flexible tubular housing terminates as aring-shaped handle.

4. A catheter as claimed in claim 3, wherein the proximal outwardlyextending end of said control wire terminates as a triangular-shapedhandle, for easy identification of the control wire. v

1. A catheter for the creation of an atrial septal defect withoutthoracotomy, comprising, in combination, a main tubular housing offlexible material having an open end and a closed end tip formed with anelongated slit open portion, a flexible guide wire displaceablelongitudinally in said main tubular housing, one end of said guide wireextending outwardly through said open end, the other end of said guidewire being secured in said closed end tip and extending outwardlythereof, said other end of the guide wire having a distal part lyingwithin said open slit portion and being deformable into a dome-shapedprotrusion upon advancing said guide wire in the direction of saidclosed end tip, a flexible control wire displaceable axially of saidmain housing and having a proximal outwardly extending end, a bladehaving one end pivoted to the distal end of said control wire, linkmeans pivoted to tHe other end of said blade and to said closed end tip,said blade and said link means being normally disposed in said slit openend and deformable into V-shape upon advancing the control wire in thedirection of the closed end tip, a branch tubular housing communicatingwith said main housing and having a free end adapted for connecting asyringe or pressure gauge, first and second stoppers of resilientmaterial secured, respectively, about the main housing forwardly andposteriorly of said branch housing for applying hemostats to preventfluid leakage, pressure and back flow of blood during the initialintroduction of the catheter into the vessels and cardiac chamber of apatient.
 2. A catheter as claimed in claim 1, wherein said guide wireconsists of a fine coiled spring wire, and a flexible solid wire securedin said coiled spring wire inwardly of the proximal part of said guidewire.
 3. A catheter as claimed in claim 2, wherein the one end of saidguide wire extending from said flexible tubular housing terminates as aring-shaped handle.
 4. A catheter as claimed in claim 3, wherein theproximal outwardly extending end of said control wire terminates as atriangular-shaped handle, for easy identification of the control wire.